Zip Code Call Blocker App

I'm looking to develop a mobile app for both iOS and Android platforms that can block phone calls from specific zip codes. The app's functionality is straightforward - when a call comes in from a blocked zip code, it will silently decline the call.

Key Features:
- Cross-platform compatibility (iOS and Android)
- Manual input for zip codes to block

Ideal Skills:
- Mobile app development (iOS and Android)
- Experience with call blocking functionalities
- UI/UX design for user-friendly interface

Please ensure your proposal includes examples of similar apps you've developed or worked on.